Hi Cory, and welcome to XF!
Re: CDN, it's something that's been suggested though it's hard to find given that it's 3 characters .
Checkout http://xenforo.com/community/threads/cdn.182/ , I'd chime in on there with your opinion.
Might I be able to ask how you are currently implementing Google App Engine as the CDN on your forum? I assume you're syncing files up there?
I've got a website running ALL static content, except jQuery, from Google App Engine. Suffice to say it's fine. However, simple template edits are sufficient to satisfy the craving for putting often used content to the CDN.
Additionally, it will help to set ETags and Expires. Many of us dive into the CDN without looking first at what can be done on the server-site side. For example, just set up a cookie-less domain and serve content from that. Not too difficult
Ive seen suggestions for CDN etc and it works great for avatars, js & attachment thumbnails. Now there is CDN support in Xenforo, I thought id make a specific request/suggestion for full sized attachments.
I have all of our attachments viewable to the public and would like to have an option for these to be served by CDN.
If its possible to use a CDN for attachments, I'm yet to find out how. As far as I understand and have seen from my personal experience, it only serves the attachment thumbnails, avatars, js and style images at this stage.
If you use a pull-origin CDN, on the first request for the file the CDN will grab the file from your server if not in cache and download it to the CDN cache. All future requests will serve that file from the CDN until it expires from cache. I've found by serving full attachments from the CDN can save up to 30% on bandwidth every day - probably more on much busier forums with more attachments.
I second that, atfer installing MaxCDN, I've noticed the full images in a post were not displayed from the cache. I've tried to search a [tricky] way without result. I guess that's something which should be changed internally, or at least an option to have the original images in /data.
Mine too - crossing fingers this gets implemented in the next release. Our bandwidth requirements have tripled from the server because of this since moving to Xenforo (was using VBSEO with CDN integration)